The conventional various systems for recognizing a face have been developed to be commercialized. The conventional systems have been designed to capture a face image of a user when the user is located at a central position in front of a camera, and to implement optimum face recognition performance when the face image is included in a “face authentication region”.
However, the conventional face recognition system may have the following problem. Since the camera is fixed at a predetermined height, when a face position of a user is out of range of the “face authentication region” due to a height of the user, face authentication may fail.
In order to solve such a problem, in the conventional face recognition system, a face image of a user is displayed on a display unit, and a face authentication region is also displayed on the display unit, thereby allowing the user to move himself or herself such that his or her face image is located within the face authentication region. This may cause user's inconvenience, and thus prevent the conventional face recognition system from being widely used.